Yttrofluorite

Yttrofluorite is a rare variety of Fluorite that contains an appreciable amount of yttrium (Y). It was first described as a new mineral species in 1911 by Norwegian geologist, Dr. Thorolf Vogt (1888-1958), under the name ‘‘yttrofluorite’’, but was discredited by the IMA in 2006 as a variety of Fluorite. It was originally reported from Hundholmen, Tysfjord, Nordland, Norway.

According to Vogt, Yttrofluorite has a higher specific gravity and poorer cleavage than Fluorite and the color is usually yellow to yellow-brown, but can also be brown or yellow-green and has a vitreous lustre on its cleavages. Yttrofluorite may also fluoresce a weak to strong white to greenish white under shortwave UV light. If you place your cursor over the picture above you will see the Yttrofluorite gem under SW UV light.

Yttrofluorite distribution: at the type locality, Hundholmen, Tysfjord, Nordland, Norway. Also in Norway at the Øvre Lapplægeret Quarry, Lapplægeret, Drag, Tysfjord, Nordland. In the USA there are several localities located in Colorado: the White Cloud Pegmatite, the Little Patsy Pegmatite, and the Big Bertha Mine, South Platte Pegmatite District and the S. B. Strang Ralston Creek Pegmatite, Jefferson County. At the Globe Pegmatite, Alamos area, Petaca District, Rio Arriba County, New Mexico. Several other localities have been reported including Janet ore occurrence, Kara-Oba W deposit, Betpakdala Desert, Karaganda Oblast’, Kazakhstan. In Russia at Ploskaya Mt, Western Keivy Massif, Kola Peninsula, Murmanskaja Oblast’, Northern Region. In the Xihuashan ore field, Dayu Co., Ganzhou Prefecture, Jiangxi Province, China.

Chemical Formula: Ca0.7Y0.3F2.3
Calcium Yttrium Fluoride
Composition: Calcium 28.50 % Ca 39.88 % CaO
Yttrium 27.10 % Y 34.41 % Y2O3
Fluorine 44.40 % F 44.40 % F
– % F -18.69 % -O=F2
  100.00 % 100.00 % = TOTAL OXIDE